A Frequency Dividing Control Strategy Considering Wind Power Fluctuation Characteristics For Automatic Generation Control Of Power System

With the increasing penetration of wind power in modern power system,the influence of wind power with fluctuating characteristics on the frequency of power system cannot be ignored.As one of the main frequency regulation methods,automatic generation control(AGC)of modern power system plays an increasingly important role.Therefore,it is significant to study the control strategy of AGC for maintaining the frequency stability of power system and improving the ability of power system to accept wind power.Aiming at the problem of continuous and violent frequency fluctuation in power system caused by large-scale wind power integration,this paper takes BLR(Base load regulated)type AGC unit with second level regulation ability as the research object,and finds that although BLR AGC units based on traditional proportional-integral(PI)control can adjust output power according to real-time frequency fluctuation,frequency fluctuation caused by high frequency component in rate fluctuation will disturb PI controller,affect its control performance,and even cause system frequency oscillation in some case.At the same time,it is found that the amplitude of wind power fluctuation decreases with the increase of frequency in the frequency domain.Hence,on the basis of considering the fluctuation characteristics of wind power and the regulation characteristics of BLR type AGC units,a power system frequency control strategy based on the principle of frequency division is proposed.The frequency signals are divided by signal frequency divider,and the primary and secondary frequency regulation process the system frequency signals in different frequency bands respectively.The stability of the control system is analysed,and the influence of the frequency divider parameters,wind power penetration,and reserve capacity on the proposed strategy is discussed.Simulation results has verified the availability of the proposed frequency regulation strategy.Finally,the validity of the proposed strategy is further verified on the test platform of power system including synchronous machine simulator,wind turbine simulator and feedback load.